Is human ontogenesis a product of evolution or a result of individual decisions and actions? In the present paper we aim at solving this apparent conflict between a behavioral genetics approach and an action-theoretical perspective to human development. After a discussion of the idea of active and intentional self-development and the role of genes in development we argue for adequate conceptualizations of development, evolution, and self-determination that allow to understand human development as a joint product of evolution and intention. The paper concludes by proposing an evolutionary developmental psychology that integrates the two positions in that it "adapts" the concept of evolution to the development of the individual.